# Блокировки (pg_locks)
https://postgrespro.ru/docs/postgresql/15/view-pg-locks

## Просмотр блокировок
```sql
SELECT
    blocked_locks.pid AS blocked_pid,
    blocked_activity.usename AS blocked_user,
    blocking_locks.pid AS blocking_pid,
    blocking_activity.usename AS blocking_user,
    blocked_activity.query AS blocked_statement,
    blocking_activity.query AS current_statement_in_blocking_process
FROM
    pg_catalog.pg_locks blocked_locks
    JOIN pg_catalog.pg_stat_activity blocked_activity ON blocked_activity.pid = blocked_locks.pid
    JOIN pg_catalog.pg_locks blocking_locks
       ON blocking_locks.locktype = blocked_locks.locktype
           AND blocking_locks.DATABASE IS NOT DISTINCT FROM blocked_locks.DATABASE
           AND blocking_locks.relation IS NOT DISTINCT FROM blocked_locks.relation
           AND blocking_locks.page IS NOT DISTINCT FROM blocked_locks.page
           AND blocking_locks.tuple IS NOT DISTINCT FROM blocked_locks.tuple
           AND blocking_locks.virtualxid IS NOT DISTINCT FROM blocked_locks.virtualxid
           AND blocking_locks.transactionid IS NOT DISTINCT FROM blocked_locks.transactionid
           AND blocking_locks.classid IS NOT DISTINCT FROM blocked_locks.classid
           AND blocking_locks.objid IS NOT DISTINCT FROM blocked_locks.objid
           AND blocking_locks.objsubid IS NOT DISTINCT FROM blocked_locks.objsubid
           AND blocking_locks.pid != blocked_locks.pid
    JOIN pg_catalog.pg_stat_activity blocking_activity ON blocking_activity.pid = blocking_locks.pid
WHERE
    NOT blocked_locks.GRANTED;
```